The goal of this project is to apply multidimensional slit-scan technology to the examination and analysis of exfoliated bladder epithelium for the detection, diagnosis, and monitoring of cancer of the urinary bladder and its precursors. Static cell slit-scan cytofluorometer studies have been performed on bladder irrigation specimens representing a variety of cellular disorders of the bladder mucosa associated with and including invasive transitional cell carcinoma. Included in this database are normal specimens, specimens from low-grade papillary transitional cell carcinoma, and high-grade invasive cancer. Static cell analyses have suggested that correct identification of abnormal specimens from the bladder can be achieved utilizing the slit-scan technique with minimal modification of existing software. Abnormal cells derived from transitional cell carcinoma are delineated from normal cells by the feature nuclear fluorescence. Atypical cells of transitional type fall in an area between the normal and clearly abnormal cell populations. Other studies are directed at identifying potential causes of false alarms and developing a protocol for staining and fixing bladder irrigation specimens. One hundred eleven specimens have been analyzed in a preliminary clinical study on a multidimensional slit-scan flow system. These included 84 specimens representing a spectrum of abnormality present in the human bladder. The system false negative rate was 4.7% and the false positive rate was 17%. Current efforts are directed toward expanding this preliminary flow database and exploring the utility of other features available from multidimensional slit-scan analysis. (3)